Culture of chlorophyllous tobacco-cells not requiring any organic additives except sucrose in the medium I. Effects of light and temperature on the growth of the cells

1. In the dark, HNG (habituated Nicotiana glutinosa) and NG cellsscarcely grew at 15?C, and the difference between the growthrates of HNG and NG was small at both 15?C and 25?C.
2. The stimulatoryeffect of light (4000 lux) on the cell growthrate was higherat 25?C than at 15?C for both HNG and NG.
3. Light exerted muchmore effect on the growth rate of HNG thanof NG.
4. The thermaleffect was higher in the light than in the darkfor both HNGand NG, and was somewhat greater on NG than onHNG.
5. The synergisticeffect of light and temperature on cell growthwas greater onHNG than on NG.
6. HNG contained more chlorophyll than NG.
7. Inaddition, there was little difference between the friabilitiesof cell groups of HNG and NG.

(Received December 3, 1976; )